Specifications

Zero-Current-Switching
Overview
The heart of Vicor’s module technology, zero-current-switching, allows Vicor converters to
operate at frequencies in excess of 1 MHz, with efficiencies greater than 80% and power
densities ten or more times those of conventional converters.
Lossless Energy Transfer
Switch turn-on of the MOSFET switch transfers a quantized energy packet from the input
source to an LC “tank” circuit, composed of inherent transformer leakage inductance of T1 and
a capacitive element, C, in the secondary. Simultaneously, an approximately half-sinusoidal
current flows through the switch, resulting in switch turn-on at zero current and turn-off when
current returns to zero. Resonance, or bidirectional energy flow, cannot occur because D1 will
only permit unidirectional energy transfer. A low-pass filter (Lo, Co) following the capacitor
produces a low ripple DC output. The result is a virtually lossless energy transfer from input to
output with greatly reduced levels of conducted and radiated noise.
12
1-800-927-9474
1-1
1st Generation
Zero-Current-Switching
Block Diagram
1
Vin
Referenced to -Vin
2.5V
REF.
Output Filter
Integrator
Vs
Ip
Vp
MOSFET
Input
Filter
OC2
OC1*
-S
TRIM
+S
E/A
+
+
–
+Vout
-Vout
Co
Lo
C
D2
D1
Reset
Control
Gate
In
-Vin
+Vin
Logic
Control
Load
C/L
OTP*
OVP*
*NOT IN VI-J00 SERIES
Gate
Out
Ip
Vp
Vs
Gate
Out
Vout
–
T1